Thank you for that info. One of the first things I checked was to make sure each server had AlwaysOn still enabled. We noticed this message in the logs:
Always On: The availability replica manager is waiting for the instance of SQL Server to allow client connections. This is an informational message only. No user action is required.
And when I did some digging online, i found this:
If you delete and re-create a WSFC cluster, you must disable and re-enable the Always On availability groups feature on each instance of SQL Server that hosted an availability replica on the original WSFC cluster.
So unfortunately since this our Production server, I will need to disable and re-enable the feature during a planned maintenance window and hope it clears up the error. 🙂